kernel/linux.git/drivers/md/md-llbitmap.c, branch v6.19.11

md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout

2026-02-26T23:00:43+00:00

[ Upstream commit d119bd2e1643cc023210ff3c6f0657e4f914e71d ] When llbitmap_suspend_timeout() times out waiting for percpu_ref to become zero, it returns -ETIMEDOUT without resurrecting the percpu_ref. The caller (md_llbitmap_daemon_fn) then continues to the next page without calling llbitmap_resume(), leaving the percpu_ref in a killed state permanently. Fix this by resurrecting the percpu_ref before returning the error, ensuring the page control structure remains usable for subsequent operations. Link: https://lore.kernel.org/linux-raid/20260123182623.3718551-3-yukuai@fnnas.com Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap") Signed-off-by: Yu Kuai Reviewed-by: Li Nan Signed-off-by: Sasha Levin

md/md-llbitmap: Remove unneeded semicolon

2025-11-08T08:55:35+00:00

Remove unnecessary semicolons reported by Coccinelle/coccicheck and the semantic patch at scripts/coccinelle/misc/semicolon.cocci. Link: https://lore.kernel.org/linux-raid/20250910091912.25624-1-nichen@iscas.ac.cn Signed-off-by: Chen Ni Signed-off-by: Yu Kuai

md/md-llbitmap: Use DIV_ROUND_UP_SECTOR_T

2025-09-11T00:18:41+00:00

When building for 32-bit platforms, there are several link (if builtin) or modpost (if a module) errors due to dividends of type 'sector_t' in DIV_ROUND_UP: arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_resize': drivers/md/md-llbitmap.c:1017:(.text+0xae8): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.c:1020:(.text+0xb10): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_end_discard': drivers/md/md-llbitmap.c:1114:(.text+0xf14): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_start_discard': drivers/md/md-llbitmap.c:1097:(.text+0x1808): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_read_sb': drivers/md/md-llbitmap.c:867:(.text+0x2080): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o:drivers/md/md-llbitmap.c:895: more undefined references to `__aeabi_uldivmod' follow Use DIV_ROUND_UP_SECTOR_T instead of DIV_ROUND_UP, which exists to handle this exact situation. Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap") Signed-off-by: Nathan Chancellor Signed-off-by: Jens Axboe

md/md-llbitmap: introduce new lockless bitmap

2025-09-06T09:27:51+00:00

Redundant data is used to enhance data fault tolerance, and the storage method for redundant data vary depending on the RAID levels. And it's important to maintain the consistency of redundant data. Bitmap is used to record which data blocks have been synchronized and which ones need to be resynchronized or recovered. Each bit in the bitmap represents a segment of data in the array. When a bit is set, it indicates that the multiple redundant copies of that data segment may not be consistent. Data synchronization can be performed based on the bitmap after power failure or readding a disk. If there is no bitmap, a full disk synchronization is required. Due to known performance issues with md-bitmap and the unreasonable implementations: - self-managed IO submitting like filemap_write_page(); - global spin_lock I have decided not to continue optimizing based on the current bitmap implementation, this new bitmap is invented without locking from IO fast path and can be used with fast disks. For designs and details, see the comments in drivers/md-llbitmap.c. Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-12-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Li Nan